RFID device for tires

Abstract

The invention concerns a patch RFID device ( 1 A, 1 B, 2, 3 ) for tires, designed to be applied to an inner liner of a tire before or after tire vulcanization/curing and comprising an innovative flexible multilayer planar structure.

The invention claimed is: 
     
       1. A patch radiofrequency identification device for tires, designed to be applied to an inner liner of a tire before or after tire vulcanization/curing and comprising a flexible multilayer planar structure including:
 a substrate; 
 a first insulating layer covering a first portion of the substrate, thereby leaving exposed a second portion thereof extending around said first portion; 
 a radiofrequency identification chip and a first antenna that are connected to each other and arranged on the first insulating layer; 
 a second antenna that is electromagnetically coupled with the first antenna and that extends, at least partially, on the first insulating layer; wherein the radiofrequency identification chip, the first antenna, and the second antenna lie on a same plane; 
 wherein the second antenna is a parasitic radiator and includes:
 a first portion that extends on the first insulating layer and is covered by the second insulating layer; and 
 a second portion that extends from the first portion on the first insulating layer and is covered by the second insulating layer, or extends from the first portion on the second portion of the substrate and is not covered by the second insulating layer; and 
 
 a second insulating layer covering the first insulating layer, the radiofrequency identification chip, the first antenna and, at least partially, the second antenna; 
 the first antenna is a two-dimensional folded structure and the second antenna is formed by an assembly of twisted conductive and non-conductive wires; 
 the first antenna and the first portion of the second antenna are relatively positioned so as to achieve electromagnetic coupling there between; 
 the first portion of the second antenna includes two ends located at opposite sides of the first antenna; 
 the second portion of the second antenna includes two straight arms extending in opposite directions from the first antenna, each from a respective end of the first portion of the second antenna; 
 the multilayer planar structure further includes a reinforcement mesh attached on the radiofrequency identification chip, the first antenna, the first insulating layer and, at least partially, the second portion of the substrate; and 
 the assembly of twisted conductive and non-conductive wires is interlaced with the reinforcement mesh so that the reinforcement mesh causes the assembly of twisted conductive and non-conductive wires to maintain shapes of the first portion and the second portion of the second antenna. 
 
     
     
       2. The patch radiofrequency identification device of  claim 1 , wherein the multilayer planar structure further includes a top rubber layer covering the second insulating layer and the second portion of the substrate, wherein said top rubber layer is designed to be applied to an inner liner of a tire. 
     
     
       3. The patch radiofrequency identification device of  claim 2 , wherein the first insulating layer is attached to the substrate via a first adhesive material/layer, and the top rubber layer is attached to the second insulating layer via a second adhesive material/layer. 
     
     
       4. The patch radiofrequency identification device of  claim 1 , wherein the multilayer planar structure is designed to be applied to an inner liner of a tire so that the inner liner covers the second insulating layer and the second portion of the substrate. 
     
     
       5. The patch radiofrequency identification device of  claim 4 , wherein the first insulating layer is attached to the substrate via a first adhesive material/layer, and the inner liner is attached to the second insulating layer via a second adhesive material/layer. 
     
     
       6. The patch radiofrequency identification device of  claim 1 , further comprising a patch formed by two or more layers, wherein said patch encapsulates the multilayer planar structure and is designed to be applied to an inner liner of a tire. 
     
     
       7. The patch radiofrequency identification device of  claim 1 , wherein the first antenna is designed to operate as a near-field coupler, and the second antenna is designed to operate as a far-field radiating antenna. 
     
     
       8. The patch radiofrequency identification device of  claim 1 , wherein the second antenna is a meander line antenna formed by a meander-line-shaped conductive wire. 
     
     
       9. The patch radiofrequency identification device of  claim 1 , wherein the radiofrequency identification chip is configured to:
 store an univocal identifier assigned to the tire in which the patch radiofrequency identification device is embedded; 
 receive, via the second antenna and the first antenna, interrogation signals from radiofrequency identification readers; and 
 transmit, via the first antenna and the second antenna, backscattered interrogation signals carrying the univocal identifier. 
 
     
     
       10. The patch radiofrequency identification device of  claim 1 , wherein the radiofrequency identification chip is configured to perform a self-tuning of a respective input impedance and/or of an input impedance of the first antenna and the second antenna so as to compensate for varying surrounding dielectric/electromagnetic conditions. 
     
     
       11. The patch radiofrequency identification device of  claim 1 , wherein:
 a temperature sensor is integrated in the radiofrequency identification chip to measure temperature values; and 
 the radiofrequency identification chip is configured to transmit, via the first antenna and the second antenna, backscattered interrogation signals carrying the temperature values measured by the temperature sensor. 
 
     
     
       12. The patch radiofrequency identification device of  claim 1 , wherein a protective resin is interposed between:
 the radiofrequency identification chip and the first antenna; and 
 the second insulating layer. 
 
     
     
       13. The patch radiofrequency identification device of  claim 1 , wherein the substrate is made of rubber, or of one or more polymeric materials, or of paper, or of textile/fabric. 
     
     
       14. A tire fitted with the patch radiofrequency identification device of  claim 1 . 
     
     
       15. The tire of  claim 14 , wherein:
 the multilayer planar structure further includes a top rubber layer covering the second insulating layer and the second portion of the substrate; 
 the top rubber layer is applied to an inner liner of the tire; 
 the first insulating layer is attached to the substrate via a first adhesive material/layer; and 
 the top rubber layer is attached to the second insulating layer via a second adhesive material/layer. 
 
     
     
       16. The tire of  claim 14 , wherein:
 the multilayer planar structure is applied to an inner liner of the tire so that the inner liner covers the second insulating layer and the second portion of the substrate, 
 the first insulating layer is attached to the substrate via a first adhesive material/layer; and 
 the inner liner is attached to the second insulating layer via a second adhesive material/layer. 
 
     
     
       17. The tire of  claim 14 , further comprising a patch formed by two or more layers, wherein the patch encapsulates the multilayer planar structure and is applied to an inner liner of the tire. 
     
     
       18. The tire of  claim 14 , wherein the first antenna is designed to operate as a near-field coupler, and the second antenna is designed to operate as a far-field radiating antenna. 
     
     
       19. The tire of  claim 14 , wherein the radiofrequency identification chip configured to:
 store an univocal identifier assigned to the tire; 
 receive, via the second antenna and the first antenna, interrogation signals from radiofrequency identification readers; and 
 transmit, via the first antenna and the second antenna, backscattered interrogation signals carrying the univocal identifier. 
 
     
     
       20. The tire of  claim 14 , wherein the radiofrequency identification chip is configured to perform a self-tuning of a respective input impedance and/or of an input impedance of the first antenna and the second antenna so as to compensate for varying surrounding dielectric/electromagnetic conditions.